The Cell and Tissue Kinetics Core was developed to facilitate skin-related research by assisting the center investigators in isolation and cultivation of primary skin cells in two and three-dimensional cultures and in analysis of genes related to skin diseases by efficient and systematic generation of transgenic tissue models of skin that show either transgene overexpression or suppression. The Specific Aims are as follows: 1. To provide assistance and training in isolation and culture of mouse and human skin cells including keratinocytes, dermal fibroblasts, melanocytes and to provide expertise in construction of three dimensional cultures of human skin from normal cells, diseased cells or transgenic cells. 2. To provide assistance and training in a variety of functional in vitro assays for keratinocyte stem cells. 3. To provide and develop proper transgenic skin models to study functional consequence of normal or mutant gene expression in human and mouse epidermis. Problems will be brought to the Cell and Tissue Kinetics Core after routine morphological analysis in the Skin Phenotyping Core or cell culture revealed an unusual finding. Findings made by the Cell and Tissue Core will be referred to the Molecular biology Core if they suggest specific changes in gene expression or other problems in molecular biology have occurred. The Cell and Tissue Kinetics Core is committed to provide both services and training for center investigators to develop necessary skills to perform these experiments in their own laboratories. The services provided by this core will benefit not only the pilot and feasibility studies included in this application but to those likely to be recruited to the Skin Diseases Research Center in the future.